Brooklyn Assemblyman William Boyland Jr. claimed to be laboring in the capital while luxuriating in Turkey, gallivanting around the Hamptons and relaxing in pricey Manhattan spas, an FBI agent testified Wednesday at the pol’s Brooklyn federal corruption trial.

Prosecutors claim that the besieged politico relentlessly turned in bogus per diem demands between 2007 and 2011, and cleared more than $70,000 in undeserved taxpayer dollars during that stretch.

An FBI agent who analyzed Boyland’s personal records testified that he lied about being in Albany a staggering 59 percent of the time over that period. Boyland even claimed to be in the capital while exploring the Turkish Sea of Marmara in October 2009.

Prosecutors presented a damning e-mail he sent to his former chief-of-staff and lover Ry-Ann Hermon that presented a picture of himself in Turkey during a “cultural exchange.”

“Our group on the Marmara Ocean — it’s sexy,” he wrote to Hermon on a day he was supposed to be moored to his Albany desk.

“Despite being in Turkey he put in for a full week of reimbursement, correct?” Assistant US Attorney Christina Dugger asked agent Vanessa Tibbits. “Yes,” she replied.

Prosecutors said that Boyland received $152,955.02 in per diem reimbursements between 2007 and 2011, but wasn’t entitled to $71,339.66 of that total.

Tibbits showed jurors a trove of evidence that Boyland was frequently everywhere but Albany on days he claimed to be working in the capital on behalf of his constituents.

The assemblyman dined across the five boroughs, from the famed Lindenwood diner in East New York to Junior’s in Brooklyn to the Bull and Bear restaurant inside the Waldorf-Astoria.

His bank records also show activity in Sag Harbor and Southampton on days he claimed to be laboring in the far less glamorous state capital in 2008.

Boyland also blew cash at the Trump Soho Spa on a day he claimed to be in Albany, prosecutors said.

The assemblyman faces up to 30 years in prison if convicted of the corruption raps against him.

In addition to the expense report, prosecutors allege that he offered political favors to undercover agents posing as agents in exchange for payola.